Tetra Sodium Salt of 1-Hydroxy Ethylidene-1&comma;1-Diphosphonic Acid &lpar;HEDP•Na4&rpar;CAS No&period; 29329-71-3 &lpar;x-Na&rpar;&comma; 3794-83-0 &lpar;4-Na&rpar; Synonyms&colon; Tetrasodium etidronate Molecular Formula&colon; C2H4O7P2Na4 Molecular weight&colon; 294 Properties&colon;HEDP•Na4 is the sodium salt of HEDP&comma; HEDP•Na4 is an good scale inhibitor for calcium carbonate&comma; it can be used in low pressure boiler water system&comma; circulating water system&comma; industrial and municipal cleaning water system and swimming pool&period; The solid HEDP•Na4 is white powder&comma; soluble in water&comma; easily deliquescence&comma; suitable for use in winter and freezing districts&period; It is a kind of organophorphonic acid scale and corrosion inhibitor&comma; can form stable complex with Fe&comma; Cu and Zn ions&comma; it can dissolve the oxides on metal surface&comma; it has good scale and corrosion inhibition effect under 250ºC&period;HEDP•Na4 is widely used in circulating cool water system&comma; medium and low pressure boiler&comma; oil field water pipelines as scale and corrosion inhibitor in fields such as electric power&comma; chemical industry&comma; metallurgy&comma; fertilizer&comma; etc&period;&period; In light woven industry&comma; HEDP•Na4 is used as detergent for metal and nonmetal&period; In dyeing industry&comma; HEDP•Na4 is used as peroxide stabilizer and dye-fixing agent&semi; In non-cyanide electroplating&comma; HEDP•Na4 is used as chelating agent&period; Specification&colon;